The present disclosure is directed to compositions for use in golf ball that has superior resistance to water and moisture vapor in comparison to conventional materials, and golf balls formed from such compositions. One conventional material used to form golf ball covers is balata, a natural or synthetic trans-polyisoprene rubber. The softness of the balata cover allows the player to achieve spin rates sufficient to more precisely control ball direction and distance, particularly on shorter shots. However, balata covers lack the durability required by the average golfer, and are easily damaged. Accordingly, alternative cover compositions have been developed in an attempt to provide balls with spin rates and a feel approaching those of balata covered balls, while also providing a golf ball with a higher durability and overall distance.
Ionomer resins (e.g., copolymers of olefin, such as ethylene, and ethylenically unsaturated carboxylic acids, such as (meth)acrylic acids, wherein the acid groups are partially or fully neutralized by metal ions) have also been used as golf ball cover materials. Ionomer covers may be virtually cut-proof, but in comparison to balata covers, they display inferior spin and feel properties.
Polyurethanes and polyureas, by providing soft “feel,” have also been recognized as useful materials for golf ball covers. However, commercially available polyurethane and polyurea compositions have properties that are undesirable for use in golf balls. For example, certain polyisocyanates and polyamines have poor weatherability, particularly prone to yellowing when exposed to UV irradiation and/or water/moisture. Some of these reagents are very volatile and pose health risks during handling and processing.
Therefore, a continuing need remains for novel material compositions usable in forming golf ball portions (e.g., covers) having desirable and/or optimal combination of physical and performance characteristics. Compositions comprising polyisocyanates and polyamines having aromatic structures and cycloaliphatic structures, such as those disclosed herein, may be suitable for forming one or more portions of the golf ball.